Marine fishes are important to health due to their high content of polyunsaturated fatty acids particularly those of the omega-3 family. These fatty acids play an important role in various physiological processes and as a consequence they may modulate and even prevent some human diseases. The aim of the present study was to investigate and compare the effect of fish oils of different origins (Sardinella longiceps, Rastrelliger kanagurta and Clarias batrachus) on lipid metabolism and membrane fluidity in diabetes. Alloxan was injected in repetitive doses for 1 month (100 mg/kg body weight every 5th day) to induce diabetes in Swiss albino mice. 10 % S. longiceps, R. kanagurta or C. batrachus fish oil was freshly blended with pellet feed which was provided to diabetic mice for 1 month. The serum lipid profile (serum total cholesterol, triglyceride, HDL, VLDL and LDL) along with liver, kidney and heart tissue lipid profile (i.e. triglyceride, total cholesterol, glycolipid and phospholipid) was analysed. Besides, the enzymatic activity of HMG-CoA reductase, HMG-CoA synthase and glucose-6-phosphate-dehydrogenase along with the membrane fluidity of these tissues was evaluated. Altered tissue lipid composition, enzyme activities and membrane fluidity due to diabetes were returned towards normal with the supplementation of 10 % fish oils. Fish oil from S. longiceps brought maximum changes in level of neutral lipid composition in heart, and increased the concentration of phospholipid and decreased the activity of HMG-CoA reductase in comparison with the fish oil from R. kanagurta and C. batrachus.

Introduction: Diabetes mellitus is a chronic disorder in human and responsible for different complications and also causes mortality and morbidity. Long chain fatty acids influence inflammation through a variety of mechanisms; many of these are mediated by, or at least associated with, changes in fatty acid composition of cell membranes. Hence the present study was performed to investigate the effect of fish oil extracted from Clarias batrachus which is a good source of PUFA n-3 among freshwater species on alloxan-induced diabetic mice. Material and method:Alloxan was administered at repetitive doses (100 mg/kg b.wt after every 5 th day for a period of one month to induce diabetes in mice. Along with alloxan injection, 10% Clarias fish oil was supplemented to diabetic mice for a period of one month. Analysis of basic antioxidant and lipid peroxidation parameters in serum, liver, kidney, heart and pancreatic tissues was carried out. Result:The levels of antioxidant and lipid peroxidation markers were significantly (P<0.05) altered in all the tissues of alloxan-induced diabetic mice. The supplementation of fish oil to diabetic mice showed significant recovery in activity of enzymes SOD, Catalase and in concentration of Vitamin C which is decreased in diabetic control mice. Conclusion:The result of this study indicated fish oil supplementation in diabetic mice helped to reduce the elevated glucose and glycosylated haemoglobin level along with an increase in insulin concentration and helped to recover the altered antioxidant and enzyme activity, which specifies that long term treatment of diabetes with fish oil may help to reduce the diabetes induced tissue damages.

Prolonged diabetes leads to multi-organ damages due to oxidative stress. Fish oil rich in omega-3 poly unsaturated fatty acid is known to reduce the oxidative stress. The present study has been aimed to evaluate the ameliorative effect of two fish oils extracted from Sardinella longiceps and Rastrelliger kanagurta, in diabetes-induced tissue damages in liver, kidney and heart tissues of mice, Mus musculus. Diabetes was induced by repetitive intra-peritoneal injection of alloxan (100mg/kg BW). The diabetic mice were fed the commercial pellet diet supplemented with 10% laboratory extracted fish oil of S.longiceps and R.kanagurta, for period of one month. Concentra-tion of various parameters viz.,Thiobutaric acid reactive substance, Vitamin C, Vitamin E and reduced glutathione along with activities of Aspartate aminotransferase, Alanine aminotransferase, Gamma glutamyltranspeptidase, Lactate dehydrogenase, Superoxide dismutase and Catalase were monitored in these tissues. Altered level of tissue biochemical composition and enzyme activities due to diabetes-induced damages was nearly brought down to nor-mal levels with the supplementation of 10% fish oil. Histological studies of liver, heart and kidney confirms the protective effect of dietary fish oil from diabetes induced tissue damages. Fish oil from S.longiceps brought maximum changes in concentration of TBARS, Vitamin C and in the activities of AST, LDH and Catalase in diabetic mice in comparison with the fish oil of R.kanagurta. Fish oil from S.longiceps offers better protective effect in diabe-tes induced mice in comparison to R. kanagurta oil.